This year, Paul Aronson, an 84-year-old from Manhattan, contacted a 17-year-old girl, Shaina Foster, through the site and took her out to dinner. On a second date, Ms. Foster brought along her twin sister, Shalaine.

For a few hours on Oct. 1, the evening looked as if it might turn into an old man’s fantasy. The three dined at an expensive restaurant in Midtown. Then Mr. Aronson invited the teenagers to have a drink with him at the four-story brick townhouse he owns on East 38th Street.

He bought a bottle of raspberry-flavored rum from a liquor store on the way, a defense lawyer said. But instead of receiving caresses or whispered flirtations, Mr. Aronson ended up tied to a coffee table for 20 hours. […]

Prosecutors say the two girls bound him with zip ties, took $470 in cash from his wallet and went on a spending spree with his credit cards, buying makeup and clothes. […]

Before he was tied up, Mr. Aronson had given the teenagers a tour of his townhouse and let them play with his tiny dog, a Yorkshire terrier named Muffins, Mr. Kennedy said. Then he poured them glasses of rum and asked them about their sex lives. […]

“He asked to do things I wasn’t going to do,” she told Detective Darryl Ng at the 17th Precinct after the girls were arrested on Oct. 21. “He is ugly, old and disgusting. I tied him up. I took his money and left. He was starting to creep me out.”